1. Field
The present invention relates to an exhaust muffler device for an engine which includes a ceramic catalyst body therein.
2. Description of the Related Art
Heretofore, catalytic units provided to exhaust muffler devices and the like have been known in which a mat as a holder is wrapped around the outer circumference of a ceramic catalyst body, and the ceramic catalyst body is held inside a cylindrical holding tube such as a metal case with the holder therebetween, as shown, for example, in Patent Document 1 (Japanese Patent Application Publication No. 2000-337139). In Patent Document 1, an exhaust pipe connected to the upstream end of the holding tube is fitted to an inner circumferential portion of the upstream end of the holding tube, and the end of an inner circumferential portion of the exhaust pipe is arranged at a position in proximity to the mat.
However, in the conventional catalytic unit described above, since the end of the inner circumferential portion of the exhaust pipe is arranged in proximity to the mat, exhaust gas that flows along the inner wall of the exhaust pipe directly hits an end portion of the mat. For this reason, there is a possibility that a large amount of exhaust gas may enter the inside of the mat and/or that the flow of the exhaust gas may become turbulent in the vicinity of the end portion of the mat.